24 Arcadis Ost 1 Wind Turbines Installed, Remaining 3 Waiting for Autumn

April 3, 2023, by Adrijana Buljan

Heerema Marine Contractors, using its giant crane vessel Thialf, has installed 24 Vestas 9.5 MW turbines at the Arcadis Ost 1 offshore wind farm in Germany. The installation of the three remaining units is now scheduled for Autumn.

Offshore construction at the project site in the Baltic Sea began in June 2022 with the installation of XXL monopile foundations and work on installing the wind turbines started in November of last year.

On 3 April, Heerema Marine Contractors announced that it completed the first installation campaign on Arcadis Ost 1, which included 24 wind turbines.

“This marks the end of the first installation campaign of the wind farm using the revolutionary floating installation method developed together with Heerema Marine Contractors and Vestas. Unfortunately, Vestas incurred delays on the deliveries of some rotor blades. The remaining three turbines will be installed upcoming Autumn, completing the 257 MW wind farm”, the offshore construction specialist said in a press release.

The offshore wind farm, owned by Belgian developer Parkwind, fed the first electricity into the German grid in mid-January. Now, most of the 24 turbines are producing electricity, according to Heerema.

The 257 MW offshore wind farm is expected to be fully commissioned at the end of this year, after the three remaining Vestas wind turbines are in place.

The Vestas V174-9.5 MW wind turbines are being installed using a novel floating installation method, called the Rotor Nacelle Assembly (RNA) method, developed by Heerema Marine Contractors.

The method involves one of Thialf’s two main cranes lifting a pre-assembled tower onto the foundation, while the second main crane is used to assemble the nacelle and the blades. Once pre-assembled, the complete RNA is placed as one piece onto the wind turbine tower in only one lift.

At Arcadis Ost 1, where the method is being employed commercially for the first time, installation cycle times were consistent and competitive with traditional methods while the floating installation introduces various specific benefits, such as zero seabed interaction which is especially important in areas of significant water depth or challenging soil conditions, according to Heerema.

Heerema’s CTO, Ramon de Haas, said: “The floating installation of Arcadis Ost 1 has demonstrated Heerema’s ability to make a real change in the offshore wind market. We continue to be committed to introducing new methodologies that can solve industry challenges”.

“The success of the RNA installation method marks a significant achievement for the offshore wind industry. Parkwind has been at the forefront of innovation in offshore wind for the last decade, and with Arcadis Ost 1 we continue to do so. As offshore wind energy targets grow, this kind of innovation is key if we want to move towards a sustainable future as fast as possible”, said Eric Antoons, co-CEO of Parkwind.

“As zones go further offshore and turbines increase in size, we are certain to see a continued demand for substantial innovation in our industry. We are delighted to be a part of this journey”.